JP7254670B2 - laminate - Google Patents

Description

The present disclosure relates to laminates.

A hot-melt adhesive composition is processed into a film or sheet and laminated on the surface of a member as an adhesive film or sheet in various industrial fields such as the electrical field, the automotive field and other industrial fields. It's being used. Acid-modified olefin-based thermoplastic resin (hereinafter referred to as "acid-modified polyolefin") for bonding metal members such as iron, aluminum, titanium and other metals and alloys thereof used in these fields It is known that the use of a hot-melt composition containing as a main component yields a joined body having relatively good adhesive strength.

For example, Patent Document 1 discloses an adhesive sealing member using an adhesive composition containing a specific acid-modified polyolefin, a thermoplastic elastomer not modified with acid, and a silane coupling agent having an epoxy group. . This obtains adhesive strength through chemical bonding between the silane coupling agent and the hydroxyl groups on the metal surface, and a joined body using the sealing member has excellent water resistance.

Patent Document 2 relates to a method for manufacturing a joined body of a metal member and a thermoplastic resin member by thermal welding under specific conditions using polyolefin, and the metal member is subjected to surface treatment such as chromate treatment. It is disclosed that the film thickness of the polyolefin is set to 0.1 to 9 mm in some cases, and that the film thickness of the polyolefin is set to 0.2 to 9 mm when the metal member is not subjected to the above surface treatment.

In Patent Document 3, a first adhesive layer, a first intermediate layer, a base layer having heat resistance, a second intermediate layer, and a second adhesive layer are laminated in this order, and the first adhesive layer and A hot-melt adhesive resin film is disclosed in which the second adhesive layer contains an acid-modified polyolefin resin.

Patent Document 4 discloses an adhesive composition containing a specific modified polyolefin (A), a glycidylamine type epoxy resin (B1), a glycidyl ether type epoxy resin (B2) and an organic solvent (C).

JP 2011-213767 A WO2014/112506 JP 2017-36354 A WO2015/190411

However, when the bonded body formed by the conventional technique is used in the presence of water, there is a problem that the penetration of water into the bonding interface accelerates the peeling, resulting in a decrease in adhesive strength in a short period of time.
Although the bonded body using the adhesive sealing member described in Patent Document 1 has relatively good water resistance, there is a problem that the bonding strength is remarkably lowered in the presence of warm water.
In the method for manufacturing a joined body described in Patent Document 2, for a low-polarity metal member having a ratio of the dipole term in the surface free energy of 5.0% or less, regardless of the presence or absence of surface treatment, polyolefin When the film thickness is less than 200 μm, there is a problem that the water resistance is inferior, and especially in the presence of warm water, the adhesive strength is significantly reduced.
In the hot-melt adhesive resin film described in Patent Document 3 and the adhesive composition described in Patent Document 4, the adhesion to the low-polarity metal member is significantly reduced, especially in the presence of warm water. There was a problem.

One embodiment of the present disclosure has been made in view of the above circumstances, and its purpose is to provide adhesion to low-polarity metal members in the presence of hot water (hereinafter sometimes referred to as “hot water resistance” ) is to provide a laminate that is excellent.

Means for solving the above problems include the following aspects.
<1> A resin substrate, an easy-adhesion layer provided on at least one surface of the resin substrate, and an adhesive resin layer provided on the surface of the easy-adhesion layer opposite to the resin substrate. , The adhesive resin layer has at least one group selected from the group consisting of an acid group and an acid anhydride group, and has an acid value of 0.01 mgKOH/g to 6.5 mgKOH/g. A laminate for adhering metal members containing a certain polyolefin and having a ratio of dipole term in surface free energy of 0.01% to 5.0%.
<2> The solubility parameter of the easy-adhesion layer is larger than the solubility parameter of the adhesive resin layer and smaller than the solubility parameter of the resin substrate, and the solubility parameter of the easy-adhesion layer and the solubility parameter of the adhesive resin layer The laminate according to <1>, wherein the absolute value of the difference between is 3.0 (J/cm ³ ) ^1/2 or less.
<3> The laminate according to <1> or <2>, wherein the easy adhesion layer has a thickness of 8 nm to 200 nm.
<4> The laminate according to any one of <1> to <3>, wherein the resin substrate has a glass transition temperature of 90° C. or higher.
<5> Having the easy-adhesion layer provided on both surfaces of the resin base material, and the adhesive resin layer provided on the surface of the easy-adhesion layer opposite to the resin base material, respectively <1 > to the laminate according to any one of <4>.
<6> The laminate according to any one of <1> to <5>, wherein the acidic group contains a carboxylic acid group.
<7> The laminate according to any one of <1> to <6>, wherein the acid anhydride group contains a carboxylic acid anhydride group.
<8> The laminate according to any one of <1> to <7>, wherein the polyolefin contains propylene units, and the content of the propylene units is 50% by mass or more relative to the polyolefin.
<9> The laminate according to any one of <1> to <8>, wherein the polyolefin has an acid value of 0.01 mgKOH/g to 3.0 mgKOH/g.
<10> The laminate according to any one of <1> to <9>, wherein the adhesive resin layer further contains a styrene-based thermoplastic elastomer.
<11> The laminate according to <10>, wherein the content of the thermoplastic styrene elastomer is 20% by mass or less with respect to the total of the polyolefin and the thermoplastic styrene elastomer.
<12> The laminate according to any one of <1> to <11>, wherein the adhesive resin layer has an acid value of 0.01 mgKOH/g to 6.5 mgKOH/g.

According to one embodiment of the present disclosure, it is possible to provide a laminate that exhibits excellent adhesive strength in the presence of warm water to a low-polarity metal member.

Hereinafter, embodiments of the present disclosure will be described in detail. The present disclosure is not limited to the following embodiments, and can be implemented with appropriate modifications within the scope of the purpose of the present disclosure.

In the present disclosure, a numerical range represented using "to" means a range including the numerical values described before and after "to" as lower and upper limits. In the numerical ranges described step by step in the present disclosure, upper or lower limits described in a certain numerical range may be replaced with upper or lower limits of other numerical ranges described step by step. In addition, in the numerical ranges described in the present disclosure, upper or lower limits described in a certain numerical range may be replaced with values shown in Examples.
In the present disclosure, "% by mass" and "% by weight" are synonymous, and "parts by mass" and "parts by weight" are synonymous.
In the present disclosure, a combination of two or more preferred aspects is a more preferred aspect.

1. Laminate The laminate of the present disclosure includes a resin base material, an easy-adhesion layer provided on at least one surface of the resin base material, and a surface of the easy-adhesion layer opposite to the resin base material. and an adhesive resin layer, wherein the adhesive resin layer has at least one group selected from the group consisting of an acid group and an acid anhydride group, and has an acid value of 0.01 mgKOH/g to A laminate for bonding metal members containing a polyolefin of 6.5 mg KOH/g and having a ratio of dipole term in the surface free energy of 0.01% to 5.0%.

The laminate of the present disclosure has an adhesive resin layer containing the specific polyolefin, so that the ratio of the dipole term in the surface free energy is 0.01% to 5.0% for a metal member It has a high adhesive strength, and by adhering it to the metal member, it is possible to reduce the penetration of water into the adhesion interface between the adhesive resin layer and the metal member. Therefore, the laminate of the present disclosure has excellent adhesion to low-polarity metal members in the presence of warm water.

1-1. Resin Substrate In the present disclosure, a resin substrate is used as a substrate for a laminate having an adhesive resin layer. The resin that constitutes such a base material can be selected according to the properties required for the base material in the intended application. The glass transition temperature (Tg) is preferably high, preferably 75° C. or higher, more preferably 90° C. or higher, and still more preferably 100° C. or higher, in order to enhance the effect of improving adhesion to the adhesive. Therefore, it is preferably a thermoplastic resin. The upper limit of the glass transition temperature of the resin substrate is preferably 200° C. or less from the viewpoint of handleability.

A glass transition temperature can be measured according to the following method.
10 mg of the sample was enclosed in an aluminum pan for measurement, mounted on a differential scanning calorimeter (TA Instruments Q100 type DSC), heated from 25 ° C. to 300 ° C. at a rate of 20 ° C./min, and heated to 300 ° C. for 5 minutes, then removed and quenched by cooling on a metal plate. This pan is again mounted on the differential scanning calorimeter, and the temperature is raised from 25° C. at a rate of 20° C./min to measure the glass transition temperature (Tg:° C.) and melting point (Tm:° C.). The glass transition temperature is the extrapolation start temperature.

The thickness of the resin substrate used in the present disclosure may be 20 μm or more, preferably 25 μm or more, more preferably 25 μm or more, in order to obtain the strength required as a substrate of a laminate having an adhesive resin layer. It is preferably 35 μm or more, more preferably 45 μm or more, and preferably 300 μm or less, more preferably 270 μm or less, further preferably 250 μm or less. Alternatively, it may be 150 μm or less, or 130 μm or less.

In the present disclosure, the resins include polyester resins, polystyrene resins, and polyamide-based resins from the viewpoints of easily obtaining the glass transition temperature as described above, favorable mechanical properties, etc., and easy handling. Polyamide resins include nylon 6 (N6), nylon 66 (N66), nylon 46 (N46), nylon 11 (N11), nylon 12 (N12), nylon 610 (N610), nylon 612 (N612), nylon 6/ 66 copolymer (N6/66), nylon 6/66/610 copolymer (N6/66/610), nylon MXD6 (MXD6), nylon 6T, nylon 6/6T copolymer, nylon 66/PP copolymer coalesced, nylon 66/PPS copolymer and the like. Among these resins, polyester resins are preferred because of their excellent moldability. That is, a polyester film is preferred as the resin substrate.

The polyester resin constituting the polyester film in the present disclosure preferably has a glass transition temperature of 75° C. or higher. By setting the glass transition temperature to 75° C. or higher, it is possible to maintain excellent adhesion to the adhesive resin layer in a moist and heat environment, leading to improved adhesion to metal members. The glass transition temperature is more preferably 90°C or higher, still more preferably 100°C or higher.
Preferred examples of such polyester resins include homopolymers of polyethylene terephthalate, polyethylene isophthalate, polybutylene terephthalate, polyethylene-2,6-naphthalate, polyethylene-2,7-naphthalate, and polybutylene-2,6-naphthalate. can be done. Preferably, the glass transition temperature is within the range of 75° C. or higher, and a copolymer may be obtained by copolymerizing other monomers. Also, the polyester resin may be a polymer blend.
Examples of copolymer components include oxalic acid, adipic acid, phthalic acid, sebacic acid, dodecanecarboxylic acid, isophthalic acid, terephthalic acid, 1,4-cyclohexanedicarboxylic acid, 4,4′-diphenyldicarboxylic acid, and phenylindanedicarboxylic acid. acid, 2,6-naphthalenedicarboxylic acid, 2,7-naphthalenedicarboxylic acid (if the main polymer is not polyethylene-2,7-naphthalate), dicarboxylic acids such as tetralindicarboxylic acid, decalinedicarboxylic acid, diphenyletherdicarboxylic acid, etc., p - oxycarboxylic acids such as oxybenzoic acid and p-oxyethoxybenzoic acid, or propylene glycol, trimethylene glycol, tetramethylene glycol, hexamethylene glycol, cyclohexanemethylene glycol, neopentyl glycol, ethylene oxide adducts of bisphenol sulfone, bisphenol Ethylene oxide adducts of A, dihydric alcohols such as diethylene glycol and polyethylene oxide glycol can be preferably used.
These compounds can be used alone or in combination of two or more. Among these, more preferred acid components are isophthalic acid, terephthalic acid, 4,4′-diphenyldicarboxylic acid, 2,6-naphthalenedicarboxylic acid, 2,7-naphthalenedicarboxylic acid, p-oxybenzoic acid, and glycol. Examples of components include trimethylene glycol, hexamethylene glycol, neopentyl glycol, and ethylene oxide adducts of bisphenol sulfone.
A preferred example of the polyester resin having a glass transition temperature of 90° C. or higher is polyethylene naphthalate. Polyethylene naphthalate may be a copolymer as long as the glass transition temperature is 90° C. or higher. Polyethylene naphthalate may also be used as a polymer blend. Among them, a polyester resin mainly composed of polyethylene-2,6-naphthalate is preferable because of its good mechanical properties and resistance to moist heat. Here, "mainly" means that 90 mol% or more, preferably 95 mol% or more of all repeating units in the polyester resin are ethylene-2,6-naphthalate units.

〔Additive〕
The resin base material in the present disclosure may contain an appropriate filler as necessary for the purpose of improving slipperiness, as long as the purpose of the present disclosure is not hindered. As the filler, those conventionally known as lubricity-imparting agents for films and sheets such as polyester films can be used. , carbon black, silicon carbide, tin oxide, crosslinked acrylic resin particles, crosslinked polystyrene resin particles, melamine resin particles, crosslinked silicon resin particles, and the like. Furthermore, colorants, antistatic agents, antioxidants, organic lubricants, catalysts, and the like can be added to the resin substrate as appropriate.

〔Production method〕
The resin base material used in the present disclosure and the resin used therein can be produced by a method conventionally known to those skilled in the art.
Hereinafter, the case of using a polyester resin as the resin will be described as a typical example. In the case of other resins, the resin substrate may be obtained by referring to the following.

(Method for producing polyester)
The polyester resin in the present disclosure can be obtained by a conventionally known method, for example, a method of directly obtaining a polyester resin with a low degree of polymerization by reacting a carboxylic acid such as terephthalic acid or naphthalenedicarboxylic acid with a glycol, a method of obtaining a polyester resin with a low polymerization degree directly by reacting a glycol with a lower alkyl ester of a dicarboxylic acid, and an ester of a glycol. It can be obtained by, for example, a method of performing polymerization in the presence of a polymerization catalyst after reaction using an exchange catalyst.

As the transesterification catalyst, one or more compounds containing sodium, potassium, magnesium, calcium, zinc, strontium, titanium, zirconium, manganese, and cobalt can be used. Polymerization catalysts include antimony compounds such as antimony trioxide and antimony pentoxide, germanium compounds such as germanium dioxide, tetraethyl titanate, tetrapropyl titanate, tetraphenyl titanate or partial hydrolysates thereof, and titanyl ammonium oxalate. , potassium titanyl oxalate, and titanium compounds such as titanium trisacetylacetonate.

When polymerization is carried out via a transesterification reaction, a phosphorus compound such as trimethyl phosphate, triethyl phosphate, tri-n-butyl phosphate, or orthophosphoric acid is added for the purpose of deactivating the transesterification catalyst before the polymerization reaction. However, from the viewpoint of the thermal stability of the polyester resin, it is preferable that the content of the phosphorus element in the polyester resin is 20 mass ppm to 100 mass ppm.

The polyester resin can also be chipped after melt polymerization and solid-phase polymerized under heating and reduced pressure or in an inert gas stream such as nitrogen.

The intrinsic viscosity (35° C., orthochlorophenol) of the polyester resin constituting the resin substrate is preferably 0.40 dl/g or more, more preferably 0.40 dl/g to 0.90 dl/g. If the intrinsic viscosity is too low, process disconnection tends to occur easily. On the other hand, if it is too high, the melt viscosity tends to be high, so melt extrusion tends to be difficult and the polymerization time tends to be long. In addition, when the intrinsic viscosity is too low, the hydrolysis resistance tends to decrease.

(Method for producing polyester film)
For the polyester film used in the present disclosure, for example, the above polyester resin is melt-extruded into a sheet, cooled and solidified with a casting drum to form an unstretched film, and the unstretched film is "Tg (unit: ° C.)" to "Tg ( Unit: ℃) + 60 ℃" in the longitudinal direction (meaning the film forming machine axis direction. It is also called the longitudinal direction or MD (Machine Direction).) Once or twice or more, the total magnification is 3 to 6 times. It is stretched in the direction of "Tg (unit: ° C.)" to "Tg (unit: ° C.) + 60 ° C." in the width direction (the direction perpendicular to the film forming mechanical axis direction and the thickness direction. The transverse direction or TD (Transverse Direction ).) Stretched once or twice or more so that the total magnification is 3 to 5 times, and if necessary, further "Tm (unit: ° C.) -80 ° C." to "Tm (unit: : ° C) -20 ° C" for 1 second to 60 seconds, and if necessary, further heat treatment at a temperature 10 ° C to 20 ° C lower than the heat treatment temperature while shrinking 0% to 20% in the width direction. Obtainable. Here, Tg represents the glass transition temperature of the polyester resin which is the raw material of the film, and Tm represents the melting point. The stretching may be sequential biaxial stretching or simultaneous biaxial stretching.

1-2. Easy-adhesion layer In the present disclosure, a layer for the purpose of easy-adhesion (hereinafter referred to as an "easy-adhesion layer") is added to at least one surface of the resin substrate in order to impart excellent adhesiveness to the resin substrate. ). Such an easy-adhesion layer may be a coating film. Such an easy-adhesion layer can improve adhesion with the adhesive resin layer of the present disclosure.

Any component that constitutes the easy-adhesion layer may be used as long as it achieves the object of the present disclosure, but the solubility parameter (SP value, hereinafter abbreviated as "SP value") is preferably between the SP value of the adhesive resin layer and the SP value of the resin substrate from the viewpoint of adhesiveness.
The SP value of the easily bonding layer is preferably larger than the SP value of the adhesive resin layer, and preferably smaller than the SP value of the resin substrate. In the above magnitude relationship of the SP value of the easy-adhesion layer, the SP value of the adhesive resin layer, and the SP value of the resin substrate, the difference between the SP value of the easy-adhesion layer and the SP value of the adhesive resin layer (that is, "easy The absolute value of "SP value of adhesive layer" - "SP value of adhesive resin layer") is preferably 3.0 (J/cm ³ ) ^1/2 or less, and 2.5 (J/cm ³ ). It is more preferably ^1/2 or less, and particularly preferably 2.0 (J/cm ³ ) ^1/2 or less. The lower limit of the absolute value of the difference between the SP value of the easy-adhesion layer and the SP value of the adhesive resin layer preferably exceeds 0 (J/cm ³ ) ^1/2 , and is 1.0 (J/cm ³ ) More preferably ^1/2 or more.

The dissolution parameter can be determined using the Fedors formula. Specifically, from the chemical structural formulas of the resin base material, the adhesive resin layer, and the easy-adhesion layer, using the Fedors calculation formula, "Polymer Engineering and Science (Polymer Eng. &Sci.)", vol. 14, No. 2 (1974), pp. 148-154, the SP value is obtained by calculation.
δi=[Ev/V] ^1/2 =[Δei/Δvi] ^1/2
Ev: Evaporation energy V: Molar volume Δei: Evaporation energy of i component atoms or atomic groups Δvi: Molar volume of i component atoms or atomic groups The SP value is obtained from the following formula as the sum of all atoms or all atomic groups.
σ=(Σei/Σvi) ^1/2

It is particularly preferable that the easy-adhesion layer is made of a composition containing at least one binder resin selected from polyester resins, acrylic resins, and polyurethane resins as a main component. Preferred examples of polyester resins include acrylic resin-modified polyester resins and vinyl resin-modified polyester resins.

Examples of components constituting the polyester resin include components derived from the following polyvalent carboxylic acids and polyvalent hydroxy compounds (that is, structural units; the same shall apply hereinafter). That is, components derived from polycarboxylic acids include terephthalic acid, isophthalic acid, orthophthalic acid, 4,4′-diphenyldicarboxylic acid, 2,5-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, 1,4 - cyclohexanedicarboxylic acid, 2-potassium sulfoterephthalic acid, 5-sodium sulfoisophthalic acid, adipic acid, azelaic acid, sebacic acid, dodecanedicarboxylic acid, glutaric acid, succinic acid, trimellitic acid, trimesic acid, trimellitic anhydride, Components derived from phthalic anhydride, p-hydroxybenzoic acid, monopotassium trimellitate, and ester-forming derivatives thereof can be used, and components derived from polyvalent hydroxy compounds include ethylene glycol, 1 , 2-propylene glycol, 1,3-propylene glycol, 1,4-butanediol, 1,6-hexanediol, 2-methyl-1,5-pentanediol, neopentyl glycol, 1,4-cyclohexanedimethanol, p -xylylene glycol, bisphenol A-ethylene glycol adduct, bisphenol A-1,2-propylene glycol adduct, diethylene glycol, triethylene glycol, polyethylene glycol, polypropylene glycol, polytetramethylene glycol, polytetramethylene oxide glycol, dimethylol Components derived from propionic acid, glycerin, trimethylolpropane, sodium dimethylolethylsulfonate, potassium dimethylolpropionate, and the like can be used. One or more of these compounds are appropriately selected, and a polyester resin is synthesized by a conventional polycondensation reaction. In addition to the above, the polyester resin may be a composite polymer having a polyester component such as an acrylic resin-modified polyester resin, a vinyl-based resin-modified polyester resin, or a polyester polyurethane obtained by chain-extending a polyester polyol with an isocyanate. good.

As a component constituting the acrylic resin, a component derived from an alkyl acrylate or an alkyl methacrylate is preferable as a main component, and the component is 30 mol% to 90 mol% with respect to the acrylic resin, and can be copolymerized. and a water-soluble or water-dispersible resin containing 70 mol % to 10 mol % of a component derived from a vinyl monomer having a functional group.

A vinyl monomer copolymerizable with alkyl acrylate or alkyl methacrylate and having a functional group has a functional group such as a carboxyl group or a salt thereof, an acid anhydride group, a sulfonic acid group or a salt thereof, an amide group or an alkylolated group. A vinyl monomer having an amide group, an amino group (including substituted amino groups), an alkylolated amino group or a salt thereof, a hydroxyl group, an epoxy group, or the like. Among these, particularly preferred functional groups are a carboxyl group or a salt thereof, an acid anhydride group, an epoxy group, and the like. Two or more of these groups may be contained in the resin.

Examples of alkyl groups of alkyl acrylates and alkyl methacrylates are methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, t-butyl, 2-ethylhexyl, lauryl and stearyl groups. , a cyclohexyl group, and the like.

As the vinyl-based monomer having a functional group that copolymerizes with alkyl acrylate or alkyl methacrylate, the following compounds having functional groups such as reactive functional groups, self-crosslinking functional groups and hydrophilic groups can be used.
Examples of compounds having a carboxyl group or a salt thereof and an acid anhydride group include acrylic acid, methacrylic acid, itaconic acid, maleic acid, metal salts of these carboxylic acids such as sodium, ammonium salts, and maleic anhydride. .
Examples of compounds having a sulfonic acid group or a salt thereof include vinylsulfonic acid, styrenesulfonic acid, metal salts and ammonium salts of these sulfonic acids with sodium or the like.
Compounds having an amide group or alkylolated amide group include acrylamide, methacrylamide, N-methylmethacrylamide, methylolated acrylamide, methylolated methacrylamide, ureido vinyl ether, β-ureido isobutyl vinyl ether, ureido ethyl acrylate, and the like. mentioned.
Compounds having an amino group or an alkylolated amino group or salts thereof include diethylaminoethyl vinyl ether, 2-aminoethyl vinyl ether, 3-aminopropyl vinyl ether, 2-aminobutyl vinyl ether, dimethylaminoethyl methacrylate, dimethylaminoethyl Examples include vinyl ethers, methylolated amino groups thereof, quaternized alkyl halides, dimethylsulfuric acid, sultone and the like.
Compounds having a hydroxyl group include β-hydroxyethyl acrylate, β-hydroxyethyl methacrylate, β-hydroxypropyl acrylate, β-hydroxypropyl methacrylate, β-hydroxyethyl vinyl ether, 5-hydroxypentyl vinyl ether, 6-hydroxyhexyl vinyl ether, polyethylene Glycol monoacrylate, polyethylene glycol monomethacrylate, polypropylene glycol monoacrylate, polypropylene glycol monomethacrylate and the like.
Examples of compounds having an epoxy group include glycidyl acrylate and glycidyl methacrylate. Other compounds having functional groups include vinyl isocyanate and allyl isocyanate.
Furthermore, olefins such as ethylene, propylene, methylpentene, butadiene, styrene, α-methylstyrene, vinyl methyl ether, vinyl ethyl ether, vinyltrialkoxysilane, acrylonitrile, methacrylonitrile, vinylidene chloride, vinyl chloride, vinylidene fluoride, Ethylene fluoride, vinyl acetate and the like are also included as vinyl-based monomer compounds.

Examples of components constituting the polyurethane resin include components derived from the following polyvalent hydroxy compounds, components derived from polyvalent isocyanate compounds, components derived from chain extenders, and components derived from cross-linking agents. . That is, components derived from polyhydric hydroxy compounds include polyethers such as polyoxyethylene glycol, polyoxypropylene glycol and polyoxytetramethylene glycol, and polyesters such as polyethylene adipate, polyethylene-butylene adipate and polycaprolactone. , polycarbonates, acrylic polyols, castor oil and the like can be used. Components derived from polyvalent isocyanate compounds include components derived from tolylene diisocyanate, phenylene diisocyanate, 4,4'-diphenylmethane diisocyanate, hexamethylene diisocyanate, xylylene diisocyanate, 4,4'-dicyclohexylmethane diisocyanate, isophorone diisocyanate, and the like. can be used. Examples of components derived from chain extenders and components derived from cross-linking agents include ethylene glycol, propylene glycol, diethylene glycol, trimethylolpropane, hydrazine, ethylenediamine, diethylenetriamine, ethylenediamine-sodium acrylate adduct, 4,4'- Components derived from diaminodiphenylmethane, 4,4′-diaminodicyclohexylmethane, water, and the like can be used. One or more of these compounds are appropriately selected, and a polyurethane resin is synthesized by a conventional polycondensation-crosslinking reaction.

Acrylic resin-modified polyester resins and vinyl resin-modified polyester resins can be synthesized by polymerizing acrylic resins or vinyl resins in an aqueous solution or dispersion of polyester. Examples of the components constituting this polyester include components derived from the same polyvalent carboxylic acids as described above, components derived from polyvalent hydroxy compounds, and components derived from ester-forming derivatives of these compounds.

As the components constituting the acrylic resin and the vinyl resin, the same components derived from alkyl acrylates as described above, components derived from alkyl methacrylates, and vinyl units similar to those described above to be copolymerized with these may be used. One or more of the components derived from the mer compound can be appropriately used.

The acrylic resin-modified polyester resin and vinyl resin-modified polyester resin of the present disclosure include those having a molecular structure such as so-called acrylic graft polyester described in JP-A-1-165633.

The content of the binder resin in the easy-adhesion layer is preferably 80% by mass or more, more preferably 90% by mass or more, relative to the total mass of the easy-adhesion layer.

In addition to the above components, the easy-adhesion layer may contain other resins such as melamine resins, antistatic agents, colorants, surfactants, ultraviolet absorbers, and the like.
The easy-adhesion layer in the present disclosure is preferably formed from a composition containing a cross-linking agent in addition to the binder resin. This further improves adhesion. As the cross-linking agent, an oxazoline-based cross-linking agent and a glycidylamine-based cross-linking agent are preferably used. The content of the cross-linking agent is preferably 3 parts by mass to 40 parts by mass, more preferably 4 parts by mass or more and 5 parts by mass or more with respect to 100 parts by mass of the binder resin, and 35 parts by mass or less and 30 parts by mass or less. more preferred.

[Method for Forming Easily Adhesive Layer]
The method for forming such an easy-adhesion layer on at least one surface of the resin substrate is not limited, and can be appropriately selected from commonly used methods. For example, the easy-adhesion layer can be formed by applying a coating liquid for forming the easy-adhesion layer to the resin substrate and drying it. It may be formed by a coextrusion method or a lamination method.

For example, when the resin substrate is a polyester film, a coating solution (an aqueous solution or aqueous dispersion, preferably an emulsion type dispersion) containing a component that forms an easily adhesive layer is applied to the stretchable polyester film, followed by drying. It can be laminated by stretching and, if necessary, heat-treating. The coating of this coating liquid may be carried out in a normal coating process, that is, in a process separated from the production process of the biaxially stretched and heat-set polyester film, but in a cleaner atmosphere, i.e. It is preferable to carry out the coating during the manufacturing process of the film, since it is less likely to involve dirt, dust, and the like. In addition, among the coatings performed during the manufacturing process of the film, coating in the state of a stretchable polyester film can further improve the adhesion of the coating film to the polyester film by subsequent stretching. preferable. Here, the "stretchable polyester film" means an unstretched polyester film, a uniaxially stretched polyester film or a biaxially stretched polyester film. Especially preferred. As the coating method, any known coating method can be applied, for example, roll coating method, gravure coating method, roll brushing method, spray coating method, air knife coating method, impregnation method, curtain coating method and the like can be used alone or in combination. can be used. The coating amount is preferably 0.5 g to 20 g, more preferably 1 g to 10 g, per 1 m ² of the running film, and the thickness of the easily adhesive layer after drying is preferably 8 nm to 200 nm, more preferably 10 nm to 100 nm. If the thickness of the easy-adhesion layer is too thin, the effect of improving the adhesion of the easy-adhesion layer tends to be low. The effect of improving adhesion to the heat seal layer tends to decrease.

1-3. Adhesive resin layer The adhesive resin layer of the present disclosure has at least one group selected from the group consisting of acidic groups and acid anhydride groups, and has an acid value of 0.01 to 6.5 mgKOH/g. It contains polyolefin (hereinafter referred to as "component (A)").

[(A) Component]
Component (A) has at least one group selected from the group consisting of acidic groups and acid anhydride groups.

Specific examples of the acidic group include a carboxylic acid group, a sulfonic acid group, a phosphoric acid group, and the like, and among these, a carboxylic acid group is preferable in terms of ease of modification.

Specific examples of the acid anhydride group include a carboxylic acid anhydride group, a sulfonic acid anhydride group and a phosphoric acid anhydride group. and carboxylic anhydride groups are preferred.

Among the above, from the viewpoint of hot water resistance, it is preferable that the acidic group contains a carboxylic acid group and the acid anhydride group contains a carboxylic acid anhydride group in the component (A).

The component (A) may be a polyolefin modified with an acid group-containing monomer and/or an acid anhydride group-containing monomer. As a method for denaturation, a known method can be employed. For example, in the presence of a radical polymerization initiator such as an organic peroxide or an aliphatic azo compound, an acidic group-containing monomer and/or an acid anhydride group-containing monomer is melted with a polyolefin having no acid group or acid anhydride group. Examples thereof include graft modification such as kneading, copolymerization of an acidic group-containing monomer and/or an acid anhydride group-containing monomer and an olefin.

(Acidic group-containing monomer)
Raw materials for component (A) include acidic group-containing monomers. Specifically, it is a compound having an ethylenic double bond and a carboxylic acid group in the same molecule, and includes various unsaturated monocarboxylic acid compounds and unsaturated dicarboxylic acid compounds.

Specific examples of unsaturated monocarboxylic acid compounds include acrylic acid, methacrylic acid, crotonic acid and isocrotonic acid.

Specific examples of unsaturated dicarboxylic acid compounds include maleic acid, itaconic acid, citraconic acid, nadic acid and endic acid.

As the acidic group-containing monomer, an unsaturated dicarboxylic acid compound is preferable, and maleic acid is particularly preferable, in terms of ease of modification.

These acidic group-containing monomers may be used alone or in combination of two or more.

When part of the acidic group-containing monomer used for modification is unreacted, in order to suppress adverse effects on adhesive strength, the unreacted acidic group-containing monomer is removed by a known method, and (A) It is preferably used as a component.

(Acid anhydride group-containing monomer)
Raw materials for component (A) include acid anhydride group-containing monomers. Specifically, it is a compound having an ethylenic double bond and a carboxylic anhydride group in the same molecule, and the acid anhydride of the unsaturated monocarboxylic acid compound and the acid anhydride of the unsaturated dicarboxylic acid compound etc.

Specific examples of the acid anhydride of the unsaturated monocarboxylic acid compound include acrylic anhydride, methacrylic anhydride, crotonic anhydride and isocrotonic anhydride.

Specific examples of acid anhydrides of unsaturated dicarboxylic acid compounds include maleic anhydride, itaconic anhydride, citraconic anhydride, nadic anhydride and endic anhydride.

As the acid anhydride group-containing monomer, acid anhydrides of unsaturated dicarboxylic acid compounds are preferable, and maleic acid anhydride is particularly preferable, in terms of ease of modification.

These acid anhydride group-containing monomers may be used alone or in combination of two or more.

If part of the acid anhydride group-containing monomer used for modification is unreacted, the unreacted acid anhydride group-containing monomer is removed by a known method in order to suppress adverse effects on adhesive strength. , (A) is preferably used as the component.

(Polyolefin with no acidic group or acid anhydride group)
Examples of raw materials for the component (A) include polyolefins having neither acidic groups nor acid anhydride groups (hereinafter referred to as "component (a1)").

Specific examples of component (a1) include polyethylene, polypropylene, random copolymers of propylene and ethylene, block copolymers of propylene and ethylene, random copolymers of ethylene and α-olefin, and blocks of ethylene and α-olefin. Examples include copolymers, random copolymers of propylene and α-olefin, and block copolymers of propylene and α-olefin. Examples of the α-olefin include 1-butene, isobutylene, 1-hexene and 1-octene.

Among them, polypropylene, block copolymer of propylene-ethylene, random copolymer of propylene-ethylene, random copolymer of propylene and α-olefin, and propylene and α-olefin Polypropylene-based polymers such as block copolymers are preferred. Furthermore, it is particularly preferred that the propylene unit content in component (a1) is 50% by mass or more.

(a1) component may use only 1 type, or may use 2 or more types together.

The acid value of component (A) is 0.01 mgKOH/g to 6.5 mgKOH/g. It is 0.01 mgKOH/g or more, more preferably 0.1 mgKOH/g or more, and particularly preferably 0.5 mgKOH/g or more, in terms of being able to impart adhesive strength to metal members. From the viewpoint of improving hot water resistance, it is 6.5 mgKOH/g or less, more preferably 3.0 mgKOH/g or less, even more preferably 2.0 mgKOH/g or less, and particularly preferably 1.0 mgKOH/g or less.
The acid value can be measured according to JIS K 0070:1992. Specifically, a sample solution is obtained by dissolving an accurately weighed sample in a mixed solvent of mixed xylene:n-butanol=1:1 mass ratio. Next, to this sample solution, a few drops of a 1 mass/volume % phenolphthalein ethanol solution are added as an indicator, and titration is performed using a 0.1 mol/L ethyl alcohol solution of potassium hydroxide as a titrant. Calculate the acid value according to the formula. In the following equation, T represents the titration volume (mL), F represents the titrant factor, and W represents the sample collection volume (g).
Acid value = (T x F x 56.11 x 0.1)/W

The melting point of component (A) is preferably 100°C to 200°C, more preferably 120°C to 180°C. The temperature is preferably 100° C. or higher in terms of improving hot water resistance, and preferably 200° C. or lower in terms of improving workability.
The melting point is measured using a differential scanning calorimeter (DSC) (e.g., TA Instruments, DSCQ100), about 20 mg of a sample is sealed in an aluminum pan for measurement, and the temperature is increased from 25 ° C. to 230 ° C. by 10 ° C./min. It can be obtained as the melting peak temperature when the temperature rate is measured.

The melt flow rate (hereinafter referred to as "MFR") of the component (A) is preferably 0.1 g/10 minutes to 30 g/10 minutes, more preferably 0, under the measurement conditions of 230°C and a test pressure of 1.96 MPa. .1 g/10 min to 20 g/10 min. It is preferably 0.1 g/10 minutes or more in terms of improving workability, and preferably 30 g/10 minutes or less in terms of improving hot water resistance.
MFR conforms to JIS K 7210:2014 and can be measured under the following conditions.
・ Apparatus: Flow tester CFT-500 (manufactured by Shimadzu Corporation)
・Dice: Φ1mm×10mm
・Test pressure: 1.96 MPa
・Cylinder area: 1 cm ²
・Cylinder temperature: 230℃

(A) Component preferably contains a propylene unit. The content of propylene units in component (A) is preferably 50% by mass or more, more preferably 80% by mass or more, relative to component (A) in terms of improving hot water resistance, More preferably, it is 90% by mass or more.

In the adhesive resin layer of the present disclosure, the component (A) may be used alone or in combination of two or more.

In the adhesive resin layer of the present disclosure, the content of component (A) is preferably 80% by mass to 100% by mass based on 100% by mass of the adhesive resin layer for the reason that it is excellent in hot water resistance. , more preferably 90% by mass to 100% by mass.

[Other ingredients]
The adhesive resin layer of the present disclosure contains component (A), but various components can be added depending on the purpose. The adhesive resin layer of the present disclosure preferably does not contain a polyfunctional isocyanate compound because the resistance to hot water may deteriorate, and the content is preferably 100 ppm or less, for example.

Other components specifically include a styrene thermoplastic elastomer (hereinafter referred to as "(B) component"), a tackifier, an antioxidant, a hindered amine light stabilizer, an ultraviolet absorber, an antistatic agent, Flame retardants, colorants, dispersants, adhesion agents, antifoaming agents, leveling agents, plasticizers, lubricants, fillers and the like. In addition, the adhesive resin layer of the present disclosure may contain a polyolefin other than the component (A) (for example, the component (a1), etc.).

These components are described below.
In addition, for the other components described later, only one type of the exemplified compounds may be used, or two or more types may be used in combination.

((B) component)
The adhesive resin layer of the present disclosure can further contain a styrene-based thermoplastic elastomer as the (B) component. Adhesive strength can be improved by further containing a styrene-based thermoplastic elastomer.

Specific examples of component (B) include styrene-butadiene copolymers, epoxy-modified styrene-butadiene copolymers, styrene-butadiene-styrene block copolymers, and styrene-ethylene/propylene-styrene block copolymers (hereinafter referred to as "SEPS"), styrene-ethylene/butylene-styrene block copolymer (hereinafter referred to as "SEBS"), styrene-isoprene/butadiene-styrene block copolymer, styrene-isoprene-styrene block copolymer, etc. styrene resins, etc., may be those having no acidic group and acid anhydride group, those having an acid group and / or an acid anhydride group, those having an amino group, good too.

A known method can be employed as a modification method for introducing an acidic group and/or an acid anhydride group. For example, in the presence of a radical polymerization initiator such as an organic peroxide or an aliphatic azo compound, graft modification such as melt-kneading the above-mentioned acidic group- and/or acid anhydride group-containing monomer with the above-mentioned styrene resin can be mentioned. be done.

A known method can be employed as a modification method for introducing an amino group. For example, terminal modification such as adding an amino group-containing compound to the living terminal of the styrene resin obtained by living anionic polymerization, organic peroxide, in the presence of a radical polymerization initiator such as an aliphatic azo compound, 2- Examples thereof include graft modification such as melt-kneading an amine compound having an unsaturated bond such as (1-cyclohexenyl)ethylamine with the styrene resin.

As the component (B), SEPS and SEBS are preferable in that both hot water resistance and workability can be achieved.

The acid value of component (B) is preferably 80 mgKOH/g or less in terms of maintaining stable quality. Furthermore, from the point of being able to improve hot water resistance, it is more preferably 50 mgKOH/g or less, particularly preferably 20 mgKOH/g or less, and may be 0.0 mgKOH/g. The acid value can be measured according to JIS K 0070:1992. Specifically, a sample solution is obtained by dissolving an accurately weighed sample in a mixed solvent of mixed xylene:n-butanol=1:1 mass ratio. Next, to this sample solution, a few drops of a 1 mass/volume % phenolphthalein ethanol solution are added as an indicator, and titration is performed using a 0.1 mol/L ethyl alcohol solution of potassium hydroxide as a titrant. Calculate the acid value according to the formula. In the following equation, T represents titration volume (mL), F represents titrant factor, and W represents sample collection volume (g).
Acid value = (T x F x 56.11 x 0.1)/W

The MFR of component (B) is preferably 1 g/10 min to 100 g/10 min, more preferably 1 g/10 min to 90 g/10 min under the measurement conditions of 230° C. and test pressure of 1.96 MPa. It is preferably 1 g/10 minutes or more in terms of improving workability, and preferably 100 g/10 minutes or less in terms of improving hot water resistance.
MFR conforms to JIS K 7210:2014 and can be measured under the following conditions.
・ Apparatus: Flow tester CFT-500 (manufactured by Shimadzu Corporation)
・Dice: Φ1mm×10mm
・Test pressure: 1.96 MPa
・Cylinder area: 1 cm ²
・Cylinder temperature: 230℃

The content of component (B) is preferably 20% by mass or less, more preferably 1% to 20% by mass, based on the total of components (A) and (B), and 1% by mass. % to 10% by mass is particularly preferred. When the adhesive resin layer contains component (B), the lower limit of the content of component (B) is not limited, and exceeds 0% by mass with respect to the total of components (A) and (B). It can be appropriately set within the range. The content of component (A) corresponding to the preferred range of the content of component (B) above is 80% by mass or more, 80% to 99% by mass, based on the total of components (A) and (B). , 90% to 99% by weight, respectively. In addition, when the adhesive resin layer contains the (B) component, the upper limit of the content of the (A) component is less than 100% by mass with respect to the total of the (A) component and the (B) component. It can be set as appropriate.
The content of component (B) is preferably 1% by mass or more from the viewpoint of excellent workability and adhesive strength, and preferably 20% by mass or less from the viewpoint of improving hot water resistance.

(Tackifier)
A tackifier can be blended for the purpose of improving adhesive strength.

Known tackifiers can be used, including terpene resins, rosin resins, aliphatic petroleum resins, alicyclic petroleum resins, copolymer petroleum resins and hydrogenated petroleum resins. be done.

Specific examples of terpene-based resins include α-pinene polymers, β-pinene polymers, and copolymers of these with phenol or bisphenol A or the like.

Specific examples of rosin-based resins include natural rosin, polymerized rosin and ester derivatives thereof.

Aliphatic petroleum resins, also called C5 resins, are generally synthesized from C5 fractions of petroleum. Alicyclic petroleum resins, also called C9 resins, are generally synthesized from C9 fractions of petroleum.

Specific examples of copolymerized petroleum resins include C5/C9 copolymerized resins.

Hydrogenated petroleum resins are generally produced by hydrogenating the various petroleum resins described above.

The content of the tackifier is preferably from 1% by mass to 20% by mass, more preferably from 1% by mass to 100% by mass of the adhesive resin layer, in terms of excellent hot water resistance. 10% by mass.

[Acid value]
The acid value of the adhesive resin layer of the present disclosure is preferably 0.01 mgKOH/g to 6.5 mgKOH/g. 0.01 mgKOH/g or more is preferable, 0.1 mgKOH/g or more is more preferable, and 0.5 mgKOH/g or more is particularly preferable in that the adhesive strength to metal members can be improved. Moreover, from the point of being able to improve hot water resistance, it is preferably 6.5 mgKOH/g or less, more preferably 3.0 mgKOH/g or less, and particularly preferably 1.5 mgKOH/g or less. The acid value can be measured according to JIS K 0070:1992. Specifically, a sample solution is obtained by dissolving an accurately weighed sample in a mixed solvent of mixed xylene:n-butanol=1:1 mass ratio. Next, to this sample solution, a few drops of a 1 mass/volume % phenolphthalein ethanol solution are added as an indicator, and titration is performed using a 0.1 mol/L ethyl alcohol solution of potassium hydroxide as a titrant. Calculate the acid value according to the formula. In the following equation, T represents titration volume (mL), F represents titrant factor, and W represents sample collection volume (g).
Acid value = (T x F x 56.11 x 0.1)/W

As a method for adjusting the acid value of the adhesive resin layer, a method of adjusting the content of component (A) in the adhesive resin layer, a polyolefin having an acid value of 0.05 mg KOH / g to 100 mg KOH / g and (a1) and a method of blending the ingredients.

[Melting point]
The melting point of the adhesive resin layer of the present disclosure is preferably 100°C to 200°C, more preferably 120°C to 180°C. The temperature is preferably 100° C. or higher in terms of improving hot water resistance, and preferably 200° C. or lower in terms of improving workability.
The melting point is measured using a differential scanning calorimeter (DSC) (e.g., TA Instruments, DSCQ100), about 20 mg of a sample is sealed in an aluminum pan for measurement, and the temperature is increased from 25 ° C. to 230 ° C. by 10 ° C./min. It can be obtained as the melting peak temperature when the temperature rate is measured.

[MFR]
The MFR of the adhesive resin layer of the present disclosure is preferably 1 g/10 minutes to 30 g/10 minutes, more preferably 5 g/10 minutes to 20 g/10 minutes under the measurement conditions of 230° C. and a test pressure of 1.96 MPa. . It is preferably 1 g/10 minutes or more in terms of improving workability, and preferably 30 g/10 minutes or less in terms of improving hot water resistance.
MFR conforms to JIS K 7210:2014 and can be measured under the following conditions.
・ Apparatus: Flow tester CFT-500 (manufactured by Shimadzu Corporation)
・Dice: Φ1mm×10mm
・Test pressure: 1.96 MPa
・Cylinder area: 1 cm ²
・Cylinder temperature: 230℃

[Method for Forming Adhesive Resin Layer]
The method for forming the adhesive resin layer is not limited and can be appropriately selected from commonly used methods. For example, a composition for forming an adhesive resin layer (hereinafter referred to as "adhesive composition") may be melt-kneaded and extruded to form an adhesive resin layer on the easy-adhesion layer. Examples of extrusion molding include a coextrusion method and an extrusion lamination method.

The adhesive composition of the present disclosure can be manufactured by known methods. Specifically, the component (A) and optionally other components are preferably mixed using a Henschel mixer, a Banbury mixer, a V-type blender, a tumbler blender, a ribbon blender, or the like, and the mixture is uniaxially mixed. By melt-kneading at 180 to 300° C., preferably 190 to 260° C. using an extruder, a multi-screw extruder, a roll, a kneader, or the like, it can be obtained in a pellet form.

The thickness of the adhesive resin layer may be appropriately set according to the material of the metal member, the application, etc., and is not particularly limited, but is preferably 10 to 200 μm, more preferably 20 to 200 μm.

The laminate of the present disclosure includes the easy-adhesion layers provided on both sides of the resin substrate, the adhesive resin layers provided on the surfaces of the easy-adhesion layers opposite to the resin substrate, It is preferred to have By providing an adhesive resin layer on each side of the laminate, two adherends can be bonded via the laminate. The compositions of the two easy-adhesion layers may be the same or different. Also, the compositions of the two adhesive resin layers may be the same or different.

1-4. Metal member The metal member is not limited as long as the ratio of the dipole term to the surface free energy is 0.01% to 5.0%. Examples include iron, aluminum, titanium, magnesium, copper, nickel, chromium, etc. A metal member containing Among these, a metal member containing titanium is preferable because of its excellent acid resistance. Specific examples of metal members include iron, aluminum, titanium, magnesium, copper, nickel, chromium, other metals, and alloys thereof. Among the above materials, titanium or a titanium alloy is preferable as the material of the metal member because of its excellent acid resistance.

From the viewpoint of excellent hot water resistance, the ratio of the dipole term in the surface free energy is preferably 0.01% to 2.5%, more preferably 0.01% to 1.5%, 0.01% to 1.0% is particularly preferred.

Here, the surface free energy of the metal member and their dispersion term, dipole term and hydrogen bond term are represented by the following abbreviations. The ratio of the dipole term to the surface free energy of the metal member is calculated by "γ _M ^P ÷γ ^M ×100".

γ _M : Surface free energy of metal member (γ _M ^D + γ _M ^P + γ _M ^H )
γ _M ^D : Dispersion term of surface free energy of metal member γ _M ^P : Dipole term of surface free energy of metal member γ _M ^H : Hydrogen bonding term of surface free energy of metal member

The above γ _M , γ _M ^D , γ _M ^P , and γ _M ^H are measured by the three-point method under the following conditions by the static drop method using a contact angle meter specified in JIS R 3257:1999. , and is calculated using the extended Fowkes formula.
Measurement temperature: 25°C
Liquids: water, α-bromonaphthalene, diiodomethane

The thickness of the metal member is not particularly limited, and may be appropriately set according to the material, application, and the like.

2. Joined body The joined body of the present disclosure is joined to the laminate and at least a part of the surface of the adhesive resin layer of the laminate, and the ratio of the dipole term to the surface free energy is 0.01% to 0.01%. and a metal member of 5.0%.

In the present disclosure, "at least part of the surface of the adhesive resin layer" means at least part of the surface of the adhesive resin layer present in the joined body of the present disclosure. In the bonded body of the present disclosure, the metal member may be bonded to at least part of the surface of the adhesive resin layer present in the bonded body of the present disclosure, and when a plurality of adhesive resin layers are present It does not have to be bonded to the surface of all the adhesive resin layers. For example, when there is one adhesive resin layer present in the joined body of the present disclosure, the metal member may be joined to a part of the surface of one adhesive resin layer. In addition, when there are a plurality of adhesive resin layers present in the joined body of the present disclosure, the metal member may be joined to a part of the surface of at least one adhesive resin layer.

Since the bonded body of the present disclosure has the adhesive resin layer and the metal member bonded together, it has a high adhesive strength. Infiltration can be reduced. Therefore, the joined body of the present disclosure has excellent hot water resistance.

The laminate and the metal member in the joined body of the present disclosure are as described in the above "1. Laminate", and the preferred ranges are also the same. A metal member may be used individually by 1 type, and may be used in combination of 2 or more type.

From the viewpoint of hot water resistance, the difference between the surface free energy of the metal member and the surface free energy of the adhesive resin layer is preferably 5.0 mN/m or more, more preferably 6.0 mN/m or more. preferable. Furthermore, from the viewpoint of peel strength, the difference between the surface free energy of the metal member and the surface free energy of the adhesive resin layer is preferably 10.0 mN/m or more. Moreover, the surface free energy of the adhesive resin layer is preferably smaller than the surface free energy of the metal member. In the joined body of the present disclosure, the difference between the surface free energy of the metal member and the surface free energy of the adhesive resin layer is calculated as "γ _M −γ _A ". From the viewpoints of maintaining stable quality, hot water resistance and peel strength, it is preferably 30 mN/m or less, more preferably 15 mN/m or less, and particularly preferably 13 mN/m or less.

Here, the surface free energy of the adhesive resin layer and their dispersion term, dipole term and hydrogen bond term are represented by the following abbreviations.
γ _A : Surface free energy of adhesive resin layer (γ _A ^D + γ _A ^P + γ _A ^H )
γ _A ^D : Dispersion term of surface free energy of adhesive resin layer γ _A ^P : Dipole term of surface free energy of adhesive resin layer γ _A ^H : Hydrogen bonding term of surface free energy of adhesive resin layer

The above γ _A , γ _AD , γ _A ^P , and γ _A ^H are measured by the three-point method under the following ^conditions by the static drop method using a contact angle meter specified in JIS R 3257:1999. , and is calculated using the extended Fowkes formula.
Measurement temperature: 25°C
Liquids: water, α-bromonaphthalene, diiodomethane

In the joined body of the present disclosure, a member other than the metal member (hereinafter referred to as "another member") may be joined to at least part of the surface of the adhesive resin layer of the laminate. Other members may be glass, thermoplastic resin, or the like.

Examples of glass include alkali glass, non-alkali glass, quartz glass, and the like.

Examples of thermoplastic resins include polyolefin-based resins, polyester-based resins, polyamide-based resins, polyacrylonitrile-based resins, polyvinyl alcohol-based resins, and polyvinyl chloride-based resins.

The shape of the metal member and other members may be appropriately set according to the application, and is not particularly limited, but may be film-like, sheet-like, plate-like, angle-like, bar-like, and the like.

The adhesive composition of the present disclosure can be used in the form of pellets, and the pellets can be used in the form of films, sheets, etc. (hereinafter referred to as "adhesive films") using a film forming machine. In addition, it is melt-kneaded at a temperature of 50°C to 200°C by a T-die method, an inflation method, a calendar method, or a screw-type extruder, and then adhered to one or both sides of the metal, glass, or thermoplastic resin member by extrusion molding. It may also be used as an adhesive film laminated with an adhesive resin layer comprising an agent composition.

When a thermoplastic resin is used as a member, it is preferable to obtain an adhesive film having a thermoplastic resin layer by extruding the adhesive composition of the present disclosure by a coextrusion method or an extrusion lamination method. .

3. Applications The laminates and joined bodies of the present disclosure can be used in various industrial fields such as electrical fields, automotive fields and other industrial fields, especially in the field of automotive batteries such as fuel cells. However, the laminate of the present disclosure may be used for applications other than fuel cells.

Examples of applications in the electrical field include decoration by attaching decorative sheets to mobile devices, television housings, white goods housings, etc., adhesion of metal members and resins, sealing of electronic parts, and the like.

Examples of applications in the automotive field include adhesion of exterior materials made of metal members and resins, genuine leather, fabric, instrument panel foam sheets and decorative sheets and bases in interior and exterior materials such as pillars, moldings, door trims, spoilers and roofs. There is adhesion of materials, etc.

Other industrial applications include adhesion between films of multilayer films such as industrial packaging and barrier films.

Examples of applications in other industrial fields include adhesion of distribution materials, building materials, daily miscellaneous goods, and sporting goods.

EXAMPLES The present disclosure will be described in detail below with reference to Examples, but the present disclosure is not limited to these. "Parts" and "%" are based on mass unless otherwise specified.

1. Measurement method [acid value]
The acid value indicates the number of milligrams of potassium hydroxide required to neutralize the acid contained in 1 g of the sample, and was measured according to JIS K 0070:1992.
Specifically, a sample solution is obtained by dissolving an accurately weighed sample in a mixed solvent of mixed xylene:n-butanol=1:1 mass ratio. Next, to this sample solution, a few drops of a 1 mass/volume % phenolphthalein ethanol solution are added as an indicator, and titration is performed using a 0.1 mol/L ethyl alcohol solution of potassium hydroxide as a titrant. Acid value was calculated according to the formula.
Acid value = (T x F x 56.11 x 0.1)/W

Here, in the above formula, T represents the titration volume (mL), F represents the titrant factor, and W represents the sample collection volume (g).

[MFR]
MFR (unit: g/10 minutes) was measured under the following conditions.
・Equipment: Flow tester CFT-500 (manufactured by Shimadzu Corporation)
・Dice: Φ1mm×10mm
・Test pressure: 1.96 MPa
・Cylinder area: 1 cm ²
・Cylinder temperature: 230℃

[Surface free energy]
JIS R 3257: By the static drop method using the contact angle meter specified in 1999, the contact angle by the three-point method is measured under the following conditions, and using the extended Fowkes formula, γ _M , γ _M ^D , γ _M ^P and γ _M ^H , and γ _A , γ _AD , γ _A ^P and γ _A ^H were calculated, ^respectively . Table 1 below shows γ _L , γ _L ^D , γ _L ^P and γ _L ^H of each liquid used in the sessile drop method.
Apparatus: CA-X type contact angle meter (manufactured by Kyowa Interface Science Co., Ltd.)
Measurement temperature: 25°C
Liquids: water, α-bromonaphthalene, diiodomethane

〔Glass-transition temperature〕
10 mg of the sample was enclosed in an aluminum pan for measurement, mounted on a differential scanning calorimeter (TA Instruments Q100 type DSC), heated from 25 ° C. to 300 ° C. at a rate of 20 ° C./min, and heated to 300 ° C. After holding for 5 minutes at , it was taken out and quenched by cooling on a metal plate. This pan was again mounted on the differential scanning calorimeter and heated from 25° C. at a rate of 20° C./min to measure the glass transition temperature (Tg:° C.) and melting point (Tm:° C.). The glass transition temperature was taken as the extrapolation start temperature.

[Thickness]
The thickness of each layer was measured according to JIS K 7130 (established in 1999).

[Dissolution parameter (SP value)]
An SP value was obtained by the following method.
From the chemical structural formulas of the resin base material, the adhesive resin layer, and the easy-adhesive layer used, using the Fedors calculation formula, "Polymer Engineering and Science (Polymer Eng. &Sci.)", Vol. The SP value was determined by calculation with reference to No. 2 (1974), pp. 148-154.
δi=[Ev/V] ^1/2 =[Δei/Δvi] ^1/2
Ev: evaporation energy V: molar volume Δei: evaporation energy of i-component atoms or atomic groups Δvi: molar volume of i-component atoms or atomic groups The SP value was obtained from the following formula as the sum of all atoms or all atomic groups.
σ=(Σei/Σvi) ^1/2

2. Physical properties of resins used Table 2 below shows the acid values and MFRs of the resins used.

3. Physical properties of the metal members used Table 3 below shows the five types of materials (M1 to M5) used as the metal members, their surface free energies, their dispersion terms, dipole terms, hydrogen bond terms, and dipoles in the surface free energy Indicates the proportion of child terms. A plate having a size of 10 mm×30 mm and a thickness of 100 μm was used as the metal member.

4. Example 1
[Production of laminate]
(Preparation of easy-adhesive agent)
An easy-to-adhesive agent (solid concentration: 4% by mass) was prepared according to the following recipe. Ion-exchanged water was used as the dilution solvent.
・Acrylic resin (manufactured by Nippon Carbide Industries Co., Ltd., trade name RX7770): 85 parts by mass ・Epoxy cross-linking agent (manufactured by Mitsubishi Gas Chemical Co., Ltd., trade name TETRAD-X): 7.5 parts by mass ・Surface activity Agent (manufactured by Sanyo Chemical Industries, Ltd., trade name Sannonic SS-70): 7.5 parts by mass

(Production of resin substrate having easy-adhesion layer)
Using manganese acetate tetrahydrate as a transesterification catalyst and antimony trioxide as a polymerization catalyst, polyethylene-2,6-naphthalate ("PEN ”) was synthesized. The obtained resin was dried with a drier at 170°C for 6 hours, then put into an extruder and melt-kneaded at a melting temperature of 300°C. After the resin was extruded through a die slit at 300°C, it was cooled and solidified on a casting drum set to a surface temperature of 25°C to prepare an unstretched film. This unstretched film was led to a roll group heated to 140°C, stretched 3.5 times in the longitudinal direction, and cooled by a roll group heated to 25°C.
On both sides of the longitudinally stretched film, the easy-adhesive agent was applied by a roll coater so that the thickness of the easy-adhesive layer in the finally obtained laminate would be 50 nm. Subsequently, while holding both ends of the film with clips, the film was introduced into a tenter, and stretched by 3.5 times in the horizontal direction in an atmosphere heated to 135°C. The film was heat-set at 220° C. for 40 seconds in a tenter, relaxed 1% in the width direction at 220° C., and then uniformly slowly cooled to room temperature to obtain a biaxially stretched film with a thickness of 200 μm.

(Formation of adhesive resin layer)
Next, an adhesive resin layer having a composition shown in Table 4 was formed by an extrusion lamination method on the easily adhesive layers on both sides of the obtained biaxially stretched film to obtain a laminate. The thickness of each adhesive resin layer obtained was 50 μm. The conditions for extrusion lamination were an extrusion temperature of 230°C.

5. Examples 2-5 and 10, and Comparative Examples 1-8
A laminate was produced in the same manner as in Example 1, except that the configuration of the adhesive resin layer and the metal member used were changed as shown in Table 4.

6. Example 6
A laminate was produced in the same manner as in Example 1, except that a resin substrate having an easy-adhesion layer was produced according to the following procedure.
Using manganese acetate tetrahydrate as a transesterification catalyst and antimony trioxide as a polymerization catalyst, polyethylene terephthalate (shown as "PET" in Table 4) having an intrinsic viscosity of 0.58 dl/g (35°C, orthochlorophenol) was used as a resin. ) was synthesized. After drying the obtained resin with a 170°C dryer for 6 hours, it is put into an extruder, melt-kneaded at a melting temperature of 300°C, extruded through a die slit at 300°C, and then on a casting drum set to a surface temperature of 25°C. was cooled and solidified to prepare an unstretched film.
This unstretched film was led to a roll group heated to 140°C, stretched 3.5 times in the longitudinal direction, and cooled by a roll group heated to 25°C.
Subsequently, an easy-adhesive agent was applied to both sides of the longitudinally stretched film in the same manner as in Example 1 by a roll coater method.
Subsequently, while holding both ends of the film with clips, the film was led to a tenter and stretched by 3.5 times in the transverse direction in an atmosphere heated to 135°C. Thereafter, the film was heat-set at 220° C. for 40 seconds in a tenter, relaxed 1% in the width direction at 220° C., and then uniformly slowly cooled to room temperature to obtain a biaxially stretched film with a thickness of 200 μm.

7. Examples 7-9
A laminate was produced in the same manner as in Example 1, except that the structure of the easy-adhesion layer was changed as shown in Table 4.

8. Evaluation Using the laminates of Examples 1 to 10 and Comparative Examples 1 to 8, peel adhesion strength and drop time in a constant load immersion test were evaluated. Table 4 summarizes the evaluation results.

[Peeling adhesive strength]
Each of the laminates of Examples 1-10 and Comparative Examples 1-8 was cut into a size of 10 mm×20 mm. A plate-like metal member selected according to Table 4 was thermally and pressure-bonded to the adhesive resin layers on both sides of each laminate to prepare a joined body. The conditions at this time were a temperature of 160° C., a pressure of 3.0 MPa, and a crimping time of 10 seconds. In addition, in the production of the joined body, one end in the longitudinal direction of the laminate is aligned with one end in the longitudinal direction of the metal member, and the metal member is thermocompression bonded to the laminate, A portion to which the adhesive resin layer was not adhered was provided at the other end of the metal member in the joined body in the longitudinal direction. After that, it was housed in an environment controlled at 25° C. for 3 days to obtain a test piece.
Of the two metal members of the obtained test piece, the portions to which the adhesive resin layer is not adhered are respectively fixed to the upper and lower chucks, and the peel adhesion strength (N/ 10 mm) was measured. The measurement conditions were a temperature of 25° C. and a tensile speed of 30 mm/min.

[Drop time of constant load immersion test (hot water resistance)]
One of the metal members of the test piece prepared in the same procedure as for peeling bond strength is hung from above using a hook to the part where the adhesive resin layer is not adhered, and the adhesive resin of the other metal member A hook was used to attach a weight to the portion where the layer was not adhered, and a load of 0.4 N/mm was applied in warm water. The test piece was immersed in hot water at 95° C. together with a weight, and the time required for the weight to fall off after the adhered portion was peeled off was measured.

From Table 4, it was found that the laminates of Examples 1-10 are superior to the laminates of Comparative Examples 1-8 in hot water resistance.

The laminate of the present disclosure can be used in various industrial fields such as the electrical field, automotive field, and other industrial fields, especially in the field of automotive batteries such as fuel cells.

Claims (12)

a resin base material;
an easy-adhesion layer provided on at least one surface of the resin base;
an adhesive resin layer provided on the surface of the easy-adhesion layer opposite to the resin substrate,
The adhesive resin layer contains a polyolefin having at least one group selected from the group consisting of an acid group and an acid anhydride group and having an acid value of 0.01 mgKOH/g to 6.5 mgKOH/g. ,
A laminate for adhering metal members in which the dipole term accounts for 0.01% to 5.0% of the surface free energy. The solubility parameter of the easy-adhesion layer is larger than the solubility parameter of the adhesive resin layer and smaller than the solubility parameter of the resin substrate, and the difference between the solubility parameter of the easy-adhesion layer and the solubility parameter of the adhesive resin layer is The laminate according to claim 1, having an absolute value of 3.0 (J/cm ³ ) ^1/2 or less. 3. The laminate according to claim 1, wherein the easy-adhesion layer has a thickness of 8 nm to 200 nm. The laminate according to any one of claims 1 to 3, wherein the resin substrate has a glass transition temperature of 90°C or higher. Claims 1 to 1, wherein the easy-adhesion layer is provided on both sides of the resin base material, and the adhesive resin layer is provided on a surface of the easy-adhesion layer opposite to the resin base material. Item 4. The laminate according to any one of items 4. The laminate according to any one of claims 1 to 5, wherein the acidic group contains a carboxylic acid group. The laminate according to any one of claims 1 to 6, wherein the acid anhydride group contains a carboxylic acid anhydride group. The laminate according to any one of claims 1 to 7, wherein the polyolefin contains propylene units, and the content of the propylene units is 50% by mass or more with respect to the polyolefin. The laminate according to any one of claims 1 to 8, wherein the polyolefin has an acid value of 0.01 mgKOH/g to 3.0 mgKOH/g. The laminate according to any one of claims 1 to 9, wherein the adhesive resin layer further contains a styrene-based thermoplastic elastomer. 11. The laminate according to claim 10, wherein the content of said thermoplastic styrene elastomer is 20% by mass or less with respect to the total of said polyolefin and said thermoplastic styrene elastomer. The laminate according to any one of claims 1 to 11, wherein the adhesive resin layer has an acid value of 0.01 mgKOH/g to 6.5 mgKOH/g.